Epitaxial growth and magnetic properties of B2-type ordered FeRh alloys

The B2-type ordered FeRh alloys exhibit a first-order phase transition from an antiferromagnetic to a ferromagnetic stale with increasing temperature. In this study, the ordered FeRh0.95Ir0.05 alloy thin films were deposited by sputtering directly onto substrates heated above 250 degrees C. Deposition on glass and MgO(0 0 1) substrates resulted in [1 1 1]-oriented polycrystal and [0 0 1]-oriented single-crystal films, respectively. The films deposited on Al2O3(0 0 0 1) substrates were [1 1 0] epitaxial or [1 1 1]-oriented ones, depending on the sputtering conditions. Those films showed the first-order magnetic transition at about 450 K. The temperature hysteresis of the transition and the Curie temperature of the films depended on the grain size and the lattice matching with the substrates. (C) 1998 Elsevier Science B.V. All rights reserved.